Older women, obesity, and pain intensity: how do they affect each other? The Pain Reporter contacted Vahid Eslami, MD, the lead author of a study examining the connections between those 3 things. Dr. Eslami is a postdoctoral research Fellow in the Department of Neurology at the Albert Einstein College of Medicine in Bronx, New York.

Q: What steered you and your research team to this research?

A: About one-fifth of Americans age 65 years or older report a pain related problem that persists for more than a day in the past 30 days. There are risk factors for pain in older adults including female gender, obesity, and inflammation. Women are twice as likely to experience chronic pain than men. Therefore, we chose to examine the role of obesity and inflammation as risk factors for pain separately in women and men. Our hypothesis was that the associations of obesity with pain intensity and pain interference may be mediated through systemic inflammation in both women and men.

"Women are twice as likely to experience chronic pain than men.”

Q: Your study highlighted older women, pain, and obesity. Did the pain lead to obesity, vice versa, or both?

A: The cross-sectional design of this study precludes conclusions regarding causality or directionality of the relationship among obesity, Q:, and pain; however, we know that obesity is a proinflammatory state characterized by the release of inflammatory compounds from adipose tissue. Therefore, there is biological plausibility for the temporal pattern of obesity causing higher inflammatory levels, which, in turn, lead to a higher risk of pain.

It is also possible for pain and obesity to have a bidirectional relationship: obesity leads to inflammation and pain, and pain decreases activity leading to obesity. For example, obesity is a major risk factor for osteoarthritis, a highly prevalent pain disorder in the elderly. On the other hand, osteoarthritis limits mobility, which can lead to an increase in body mass index (BMI).

Q: How did you recruit women for your study?

A: Our sample consisted of participants from the Einstein Aging Study (EAS), a community based, longitudinal study of adults aged 70 years and older. Participants were systematically recruited from Bronx County, New York using Medicare eligibility information and voter registration lists.

Q: What are the next steps in this research? Do you plan on bringing men into the equation?

A: The next step is to look at these relationships using longitudinal methods. So, we would track BMI, inflammatory markers, and pain in participants over time and see how changes in BMI and inflammation would impact pain.

Actually, we already have brought men into the equation. Unlike women, obesity and inflammation was not associated with pain intensity or pain interference among men.

Q: What are the possible explanations of this sex difference of your study?

A: Compared to men, women have more adipose tissue, a higher percent body fat at a given BMI, and demonstrate a stronger association between adiposity and low-grade systemic inﬂammation. This suggests that the higher amount of adipose tissue in women might be associated with increased production of inflammatory markers, leading to more pain.

“The higher amount of adipose tissue in women might be associated with increased production of inflammatory markers, leading to more pain.”

A:

Sex hormones offer another potential explanation. Studies have shown an inhibitory effect of both estrogen and testosterone on inflammation. Because of the conversion of androgens to estrogen, older men actually have higher estrogen levels compared with age-matched, postmenopausal women. Thus, perhaps the higher estrogen and testosterone levels in older men compared to older women help protect against the inflammation associated with obesity.

Q: How would you like these results to change/adapt how patients are handled in practices and hospitals?

A: In corroboration with the present study, a previous study in the EAS reported that obesity was associated with a 2-fold increased risk of chronic pain, while morbid obesity (BMI≥35) was associated with 4-fold increase in the risk of chronic pain. Clinicians need to take the patient’s BMI into consideration when treating or preventing chronic pain, particularly in women. In addition to any pharmaceutical treatment, clinicians need to really stress the importance of weight loss in overweight individuals and offer strategies to do so.

Q: What do you think about the general state of pain management in the US today?

A: If we know the mechanism of how pain is produced, we can better manager it. Suppressing the pain without knowing the etiology is not an appropriate approach.

Q: In a perfect world, how would you like to the results of this study used by practitioners and patients?

A: Clinicians should conduct blood tests for specific markers and advise upon weight control strategies when necessary in order to better treat or reduce the risk of chronic pain.

Q: When you’re not working, how do you spend your free time?

A: I spend free time with friends and explore the outdoors while camping and hiking. I love plants and animals and take care of a number at home. I work on learning a new language.

Q: What is a dream project you hope to work on?

A: The dream project I hope to work on is a longitudinal and comprehensive pain study, considering obesity and obesity related inflammatory markers including IL-6, CRP, and adipocytokines, such as leptin, resistin, adiponectin, and also to examine the effects of estrogen, androgen, and testosterone hormones.